<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    
</body>
</html>
<script>
    var ss = "我是\"JavaScript\",JavaScript是一门弱类型语言";
		console.log(ss);
		console.log(ss.indexOf("Java"));
		console.log(ss.slice(15,25));
		console.log(ss.slice(28));
		console.log(ss.replace("\"JavaScript\"","张三"));
		console.log(ss.replace("\"JavaScript\"","张三").toUpperCase());
</script>